• Journal of Korean Society of Transportation
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• v.26 no.4
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• pp.173-184
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• 2008

Development of an accident estimation model based on accident data can be made after accident occurrences. However, the taking of historical accident data is not easy, and there have been differences between real accident data and police-reported accident data. Also, another difficult shortcoming is that historical traffic accident data better consider driver behavior or intersection characteristics. A new method needs to be developed that can predict accident occurrences for traffic safety improvement in black spots. Traffic conflict decision techniques can acquire and analyze data in time and space, requiring less data collection through investigation. However, there are shortcomings: as existing traffic conflict techniques do not operate automatically, the analyst's opinion could easily affect the study results. Also, existing methods do not consider the severity of traffic conflicts. In this study, the authors presented traffic conflict decision criteria which consider conflict severity, including opposing left turn traffic conflict and cross traffic conflict decision criteria. In order to test these criteria, the authors acquired three signalized intersection images (two intersections in Sungnam city and one intersection in Paju) and analyzed the acquired images using image processing techniques based on individual vehicle tracking technology. Within the analyzed images, level 1 conflicts occurred 343 times over three intersections. Some of these traffic conflicts resulted in level 3 conflict situations. Level 3 traffic conflicts occurred 25 times. From the study results, the authors found that traffic conflict decision techniques can be an alternative to evaluate traffic safety in black spots.

• Journal of Korean Society of Transportation
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• v.17 no.4
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• pp.9-17
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• 1999

교통문제는 과거에 비하여 보다 복잡해지고 다양해지고 있으며, 이러한 교통문제를 해결하기 위한 방안을 도출하는 분석기법 또한 다양해지고 있다. 이러한 기법중 안전도 평가기법에 관한 연구는 선진국에서는 1970년대부터 진행되어 왔으나, 이에 반하여 국내에서는 최근에서야 안전도에 대한 문제가 부각되면서 이에 대한 연구가 시작되고 있는 실정이다. 본 논문은 국내 외 연구사례를 중심으로 교통상충기법(TCT)을 소개하였고, 가장 진보된 방법인 스웨덴의 상충분석기법을 기반으로 국내에 적용할 수 있도록 모형을 개발하고 심각한 정도에 따라 4개 죤으로 분류하여 위험순위를 평가할 수 있는 방법을 제시하였으며, 실제로 이러한 상충분석기법을 국내의 3개 교차로 분석에 적용하여 보았다. 사고와 상충간의 conversion factor는 수집된 자료의 부족으로 사고자료의 심각도까지는 고려하지 못하였으 나, TA값을 구하고 4개죤 분류를 통하여 위험순위를 분석하여 교차로의 안전도평가에 이용할 수 있음은 보여주었다. 상충조사 분석은 안전도 평가를 저 비용과 짧은 시간내에 보다 상세한 결과를 도출할 수 있다는 점과 대상지의 사전 후 단기간 평가 방법에 가장 효과적인 기법이라는 측면에서 국내 안전도 평가에 많이 적용되기를 바란다.

• International Journal of Highway Engineering
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• v.9 no.4
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• pp.83-92
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• 2007

In 2004, the number of traffic crashes and deaths in Korea are 220,755 and 6,563, respectively. Korea Road Traffic Safety Authority reported that the number of traffic accidents occupies over 25% out of total accidents, and found that traffic crash probability is extremely high at intersections since intersections have various traffic conflict points. A Safety study using Traffic Conflict Technique is much more useful than a study using reported traffic accident data. Existing traffic conflict research hardly considered conflict severity occurring at intersections. So, the study developed new criteria considering conflict severity. Analytic methods precisely detecting crashing points using field surveying data, and applied an application of our new criteria. Opposing left-turn conflict criteria was devided by three groups(high severe conflict, middle severe conflict, and less severe conflict) based on conflict boundary by means of a standard vehicle length. After analyzing field surveying data(3hours), we found totally 41 opposing left-turn conflicts. 3 cases are high severe conflict, and another 10 cases are middle severe conflicts, and the other cases are less severe. Studies related in conflict severity are considerably important to evaluate intersection's detailed safety index, and existing studies(purely conflict counting does not consider severity) have a limitation to clearly determine the level of safety of intersections for an application.

• Journal of Korean Society of Transportation
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• v.20 no.1
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• pp.55-63
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• 2002

It has been known well that Traffic Conflict Technique(TCT) used to evaluate the safety of intersections in the case of shortage of traffic accidents data and surveying time. Because data for using in traffic conflict technique that is collected by trained surveyors, it is rely on the knowledge, experience and the characteristics of them. The data of surveying generate varying result. So, its variance must minimize and then it is considered of calculating in traffic conflict technique however obviously technique to minimize has not developed until now. So, this paper has a focus on the technical method to minimize the variance. For this, it applied the fuzzy reasoning theory to the existed traffic conflict technique that is the most comprehensive method in the country and then developed the new traffic conflict technique model. Fuzzy reasoning theory is a very appropriate method for minimizing the variance among surveyors because it can systematically calculate the uncertainty of surveyors by approximation reasoning structure. The result of analysis from pilot study, the new Procedure in this Paper minimized the variance by 53 Percentiles and it increased the value of conversion factor two times than the exited traffic conflict technique. The method proposed in this paper, it can be used for evaluating the safety of intersection, and before and after analysis of improving Project of black spots.

• Journal of Korean Society of Transportation
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• v.27 no.2
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• pp.207-214
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• 2009

This study proposed an advanced warning information system based on real-time traffic conflict analysis. An algorithm to detect and analyze unsafe traffic events associated with car-following and lane-changes using individual vehicle trajectories was developed. A positive guidance procedure was adopted to provide warning information to alert drivers to hazardous traffic conditions derived from the outcomes of the algorithm. In addition, autoregressive integrated moving average (ARIMA) analyses were conducted to investigate the predictability of warning information for the enhancement of information reliability.

• Journal of Korean Society of Transportation
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• v.20 no.2
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• pp.105-115
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• 2002

For many rears, traffic accident statistics are the most direct measure of safety for a signalized intersection. However it takes more than 2 or 3 yearn to collect certain accident data for adequate sample sizes. And the accident data itself is unreliable because of the difference between accident data recorded and accident that is actually occurred. Therefore, it is rather difficult to evaluate safety for a intersection by using accident data. For these reasons, traffic conflict technique(TCT) was developed as a buick and accurate counter-measure of safety for a intersection. However, the collected conflict data is not always reliable because there is absence of clear criteria for conflict. This study developed objective and accurate conflict criteria, which is shown below based on traffic engineering theory. Frist, the rear-end conflict is regarded, when the following vehicle takes evasive maneuver against the first vehicle within a certain distance, according to car-following theory. Second, lane-change conflict is regarded when the following vehicle takes evasive maneuver against first vehicle which is changing its lane within the minimum stopping distance of the following vehicle. Third, cross and opposing-left turn conflicts are regarded when the vehicle which receives green sign takes evasive maneuver against the vehicle which lost its right-of-way crossing a intersection. As a result of correlation analysis between conflict and accident, it is verified that the suggested conflict criteria in this study ave applicable. And it is proven that estimating safety evaluation for a intersection with conflict data is possible, according to the regression analysis preformed between accident and conflict, EPDO accident and conflict. Adopting the conflict criteria suggested in this study would be both quick and accurate method for diagnosing safety and operational deficiencies and for evaluation improvements at intersections. Further research is required to refine the suggested conflict criteria to extend its application. In addition, it is necessary to develope other types of conflict criteria, not included in this study, in later study.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.5
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• pp.64-76
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• 2008

To increase road safety at blackspots, it is needed to develop a new method that can process before accident occurrence. Accident situation could result from traffic conflict. Traffic conflict decision technique has an advantage that can acquire and analyze data in time and confined space that is less through investigation. Therefore, traffic conflict technique is highly expected to be used in many application of road safety. This study developed traffic conflict decision program that can analyze and process from signalized intersection image. Program consists of the following functional modules: an image input module that acquires images from the CCTV camera, a Save-to-Buffer module which stores the entered images by differentiating them into background images, current images, difference images, segmentation images, and a conflict detection module which displays the processed results. The program was developed using LabVIEW 8.5 (a graphic language) and the VISION module library.

• Journal of Korean Society of Transportation
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• v.28 no.4
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• pp.7-18
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• 2010

This study analyzed the relative vehicle speed and vehicle deceleration time caused by traffic conflicts using vehicle speed data at expressway toll gates and traffic conflict occurrence data. According to the analysis, the greater the relative vehicle speed is at the toll gate, the more sudden vehicle deceleration occurs due to traffic conflicts. In particular, a comparison study of cases in similar operating conditions presents a finding that usage of lanes influences traffic conflict occurrences as well as relative vehicle speed. With this finding, the study further conducted a quantitative analysis of the accident rates in relation to the relative vehicle speed between vehicles using a "Hi-Pass" lane and a regular lane at the toll gate. It indicates that when the relative vehicle speed is greater, the accident rate is higher due to sudden vehicle deceleration and shorter deceleration time. Furthermore, when the expressway entrance/exit point is closely located to a toll gate and the relative vehicle speed is great, a analysis at a traffic conflict shows a low value.

• Journal of Korean Society of Transportation
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• v.29 no.4
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• pp.17-28
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• 2011

This study proposed a speed management strategy for the enhancement of traffic safety on freeways. A novel feature of the proposed strategy is to provide desirable speed information to individual vehicles. A microscopic traffic simulator, VISSIM, was used for the performance evaluation. Vehicle trajectory data were used to evaluate the various speed management scenarios including the different levels of proportions of heavy vehicles. The proposed speed management strategy would be a useful precursor for developing an effective traffic control and operations system to prevent traffic accidents on freeways.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.11a
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• pp.57-58
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• 2023

우리나라 연안해역에 급증하는 해상풍력단지 등 대규모 해양개발 행위로 인해 무분별한 해역을 점용하게 됨에 따라, 과거 관습적으로 이용해오는 해상교통로와 상충되어 발생하는 사회적 충돌이 문제가 되고 있다. 특히, 선박 대형화 및 자동화, 자율운항선박 등장 등 해상교통환경 변화에 따라 안전한 연안 해상교통환경 조성이 시급한 상황이다. 모든 연안해역의 해상교통 흐름 및 교통밀집도 분석에 따른 관습적 해상교통망을 식별하고, 이를 지정·구축하고자, 빅데이터 및 지리정보시스템(GIS) 기반 해양공간분석기법을 활용하여 검토 및 분석하였다. 이렇게 분석 및 식별된 결과는 DB화하여 디지털 GIS 관리시스템과 연계하도록 추진중이다.